1. Field of the Invention
The field of art to which this invention relates is structural elements, and more particularly to applications for lightweight structural elements having a cavity in which a non-compressible material is disposed resulting in a rigid structure and/or one capable of vibration damping.
2. Description of the Related Art
It is highly desirable to build high speed machinery which are very accurate with structural elements that are light weight, have a high degree of stiffness, and have high internal damping characteristics. This is in fact the case for any product that is subjected to internally and/or externally induced vibrational excitation. With such structural elements, one can then design machines, structures, and other similar devices that are very accurate, that are lighter, and that can operate at higher speeds. This leads to a significant increase in performance.
In the prior art, when vibration becomes a factor, designers had the option of either adding various combinations of mass and viscoelastic material to the structure to employ a passive damper or employ some type of active damping device, such as a piezoelectric device. While the prior art passive damping devices have their advantages, they suffer from the disadvantage of greatly increasing the weight of the structure. This results in a reduction in the attainable speed of the machine or device. Active dampers, on the other hand, are usually lighter but greatly increase the cost of the machine as well as the cost of its operation.
For the above reasons, there is a need in the art for a low weight, low cost structural element that is very rigid and has high internal damping.
Therefore, it is an object of the present invention to provide a light weight structural element.
It is a further object of the present invention to provide a low cost structural element.
It is yet a further object of the present invention to provide a light weight structural element that provides for increased rigidity over comparable weight structural elements.
It is still yet a further object of the present invention to provide a structural element that is light weight and has high internal damping.
Accordingly, a pump is provided. The pump comprises: an enclosure having a first wall and two or more second walls surrounding a cavity, the enclosure further having an inlet and outlet each in fluid communication with the cavity; a first means for restricting a fluid to flow only into the cavity through the inlet; a second means for restricting the fluid to flow only from the cavity through the outlet; wherein the second walls each having at least a portion thereof shaped such that a force acting on the first wall tending to deflect the element causes an amplified deflection of the second walls into the cavity, thereby forcing fluid from the cavity through the outlet and drawing fluid into the cavity through the inlet.
In a first version of the pump, the second walls are outwardly shaped away from the cavity and the force is a tensile force acting on the first wall tending to elongate the enclosure by the deflection.
In a second version of the pump, the second walls are inwardly shaped towards the cavity and the force is a compressive force acting on the first wall tending to compress the enclosure by the deflection.
In a preferred implementation of either of the first or second versions of the pump, the first means comprises a one-way valve disposed in the inlet and the second means comprises a one-way valve disposed in the outlet. In a yet more preferred implementation, the pump further comprises an input actuator for applying the force to the first wall, wherein the input actuator is a piezoelectric actuator.
Also provided is a structure comprising at least one structural component. The at least one structural component having at least one structural element for resisting deflection of the structure. The structural element having an internal cavity for storage of a fluid which is consumed with time, the ability of the at least one structural element to resist deflection being based upon the amount of fluid contained in the internal cavity.
Preferably, the structural component comprises a plurality of structural elements, at least two of which having an opening connecting their respective internal cavities. More preferably, each of the plurality of structural elements have the opening connecting it to the internal cavity of another structural element such that the plurality of internal cavities operate as a single cavity.
The at least one structural element of the structure preferably comprises: an enclosure having a first wall and two or more second walls surrounding the internal cavity; wherein the second walls each having at least a portion thereof shaped such that a force acting on the first wall tending to deflect the element causes an amplified deflection of the second walls into the cavity, thereby exerting a compressive force against the fluid in the internal cavity, resulting in a resistance to the deflection and the first force tending to deflect the element.
In a first version of the structural element of the structure, the second walls are outwardly shaped away from the internal cavity and the force is a tensile force acting on the first wall tending to elongate the element by the deflection.
In a second version of the structural element of the structure, the second walls are inwardly shaped towards from the internal cavity and the force is a compressive force acting on the first wall tending to compress the element by the deflection.
Yet further provided is a first structural element. The first structural element comprises:
an enclosure having a first wall and two or more second walls surrounding a cavity, the enclosure further having an internal wall separating the cavity into first and second portions, the internal wall having an orifice providing communication between fluid disposed in the first and second portions; wherein the second walls each have at least a portion thereof shaped such that a force acting on the first wall tending to deflect the element causes an amplified deflection of the second walls into the cavity, thereby exerting a compressive force against the fluid, resulting in a resistance to the deflection and the force tending to deflect the element.
In a first version of the first structural element, the second walls are outwardly shaped away from the cavity and the force is a tensile force acting on the first wall tending to elongate the element by the deflection.
In a second version of the first structural element, the second walls are inwardly shaped towards the cavity and the force is a compressive force acting on the first wall tending to compress the element by the deflection.
Also provided is a second structural element comprising: an enclosure having a first wall and two or more second walls surrounding a cavity; and a fluid disposed in the cavity; wherein the second walls each having at least a portion thereof shaped such that a force acting on the first wall tending to deflect the element causes an amplified second deflection of the second walls into the fluid, thereby exerting a second compressive force against the non-compressible material, resulting in a resistance to the first deflection and the first compressive force tending to compress the element. The second structural element further comprises pressuring means for varying the pressure of the fluid in the cavity to thereby vary the resistance to the deflection.
In a first version of the second structural element, the second walls are outwardly shaped away from the cavity and the force is a tensile force acting on the first wall tending to elongate the element by the deflection.
In a second version of the second structural element, the second walls are inwardly shaped towards the cavity and the force is a compressive force acting on the first wall tending to compress the element by the deflection.
In either of the first or second versions of the second structural element, the pressure of fluid in the cavity is increased to thereby increase the resistance to the deflection or alternatively, the pressure of fluid in the cavity is decreased to thereby decrease the resistance to the deflection.
Still yet further provided is method for storing and releasing energy in a structural element where the structural element comprises an enclosure having a first wall and two or more second walls surrounding a cavity, and a fluid disposed in the cavity, wherein the second walls each having at least a portion thereof shaped such that a deflection of the first wall causes an amplified second deflection of the second walls into the fluid. The method comprises the steps of;
deflecting the first wall into a deflected position; locking the structural element in the deflected position; and releasing the structural element from the deflected position.
Where the second walls are inwardly shaped towards the cavity, the deflecting step preferably comprises withdrawing a portion of the fluid from the cavity, the locking step preferably comprises preventing the withdrawn fluid from returning to the cavity, and the releasing step preferably comprises returning the withdrawn fluid to the cavity.
Where the second walls are outwardly shaped away from the cavity, the deflecting step preferably comprises adding fluid to the cavity, the locking step preferably comprises preventing the added fluid from leaving the cavity, and the releasing step preferably comprises withdrawing the added fluid from the cavity.